<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

</body>

</html>
<script>
    var str = "hello world 我爱你!"
    function fun(str) {
        var newStr = str.split("")
        newStr = newStr.reverse()
        newStr = newStr.join("")
        newStr = newStr.replace(/\s*/g, "")
        newStr = newStr.replace("!","啊")
        newStr = newStr.replace("h","H")
        newStr = newStr.replace("w","W")
        console.log(newStr);
    }
    fun(str)
</script>